WASHINGTON D.C. — The room where baseball’s owners granted Rob Manfred a four-year extension Wednesday was off the main lobby of the luxurious St. Regis hotel, near the White House. One flight downstairs, right across from the bathrooms, was a basic poster-board sign with an arrow pointing to what Manfred believes is the most vital work remaining in his time as commissioner. “Committee on Economic Reform,” it read. “I am pleased to have another term, I really am,” Manfred told The Athletic Wednesday afternoon, once his contract had been extended to Jan. 25, 2029. “I feel like...